The invention relates to a process for continuously producing a rolled metal strip from a metal melt, in particular a steel strip, in which, in a first production step, melt is introduced into a strip-casting device, and a cast metal strip with a strip thickness of less than 20 mm, preferably between 1 mm and 12 mm, and a predetermined strip width exits from the strip-casting device, and in a second, subsequent production step, the cast, undivided metal strip is roll-deformed in at least one rolling stand until it reaches its final strip thickness. The metal strip is positioned in the roll nip by a strip diversion mounted upstream of the rolling stand. The invention also relates to an apparatus for carrying out this process, and to a method for starting up this installation.
A process of this type and a corresponding apparatus for producing a rolled steel strip from a steel melt, in which a thin cast strip is produced using the two-roller casting process using a two-roller casting device, and is hot-deformed directly from the hot casting stage in a direct further processing step carried out in a rolling stand, are already known from EP-B 540 610 and EP-A 760 397.
Furthermore, it is known from EP-B 540 610 to provide pinch roll stands at a plurality of locations in the production installation, in order to ensure reliable transportation of the cast strip from the two-roller casting machine to the strip-winding device. A diverting roll for adjusting the strip conveying after it leaves the looping pit is also provided immediately downstream of the two-roller casting installation and before the first pinch roll stand. This first pinch roll stand is intended to prevent transverse migratory movement of the strip in the installation. However, this is only possible within a limited conveying section. Furthermore, pinch roll stands are positioned upstream and downstream of trimming shears, in order to keep the steel strip under tension during longitudinal trimming.
EP-A 760 397 likewise discloses a two-roller casting installation with a downstream rolling stand for in-line deformation of the metal strip. According to one of the embodiments described, a pair of pinch rolls is mounted at a distance upstream of the rolling stand, in order to keep the cast strip under tension on the entry side of the rolling stand. In addition a dancer roll is positioned in a strip loop, between the pair of pinch rolls and the rolling stand, in order to avoid a meandering strip path when it enters the rolling stand (FIG. 3). According to a further embodiment, a plurality of diverting or pinch rolls are arranged, as required, at a successive distance from one another in a temperature-controlled region upstream of the rolling stand, in order to avoid this disruptive strip path (FIG. 7). 